Chromatography Apparatus

ABSTRACT

Disclosed is a chromatography system (100) comprising: plural modules (1-25) including at least one pump and a column valve unit (8) connectable to plural chromatography columns; and a controller (600), the controller being operable to control the or each pump and the column valve to perform different chromatographic processes, including chromatography employing just one column, as well as chromatography employing just one column, as well as chromatography employing two or more columns by selective valve opening in said unit. The system includes a housing (110) into which the plural modules (1-25) are interchangeably mountable in apertures of one generally vertical face of housing, the modules are adapted for selective fluidic interconnection by tubing substantially at said one face such that in use the modules and tubing occupy a generally vertically extending volume to minimize the footprint of the system.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/647,983, filed Mar. 17, 2020, which claims the priority benefit ofPCT/EP2018/075693, filed Sep. 21, 2018, which claims the prioritybenefit of Great Britain Application No. 1715403.0, filed Sep. 22, 2017,the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to liquid chromatography apparatus, inparticular but not exclusively to a laboratory or ‘benchtop’ sizeinstrument of a versatile nature allowing convenient reconfiguration fordifferent chromatographic procedures and convenient automated use. Theinvention extends to methods for operating such instruments.

BACKGROUND

Liquid chromatography is a well-known procedure for separating mixturesof molecules, for example separating proteins in liquid samples. Theproteins may typically be suspended in a fluid, and driven through achromatography separation medium along with a buffer solution. Thevarious sample molecules of the mixture travel at different speedsthrough a chromatography medium, causing them to separate. Thisseparation may be completed by a fractionation step where the mobilephase may be directed to different containers, e.g. by an outlet valveof the chromatography apparatus.

In some applications, e.g. in the biopharmaceutical field, recentadvancements in genetic engineering and cell culture technology havedriven expression levels higher than ever, putting a considerable burdenon down-stream purification, especially the fractionation step. Whilethe introduction of new chromatography media compositions significantlyimproves the efficiency of a process based on a conventional fixed bedchromatography, additional gains can be achieved by operating in acontinuous manner. The latter is especially appealing when continuousbioreactors, such as those operated in perfusion mode, are employed.

In continuous chromatography, two or more identical columns areconnected in an arrangement that allows columns to be operated in seriesand/or in parallel, depending on the method requirements. Thus, allcolumns can be run in principle simultaneously, but in different stages.The procedure may be repeated, such that each column is loaded/packed,eluted, and regenerated several times in the process. Compared to‘conventional’ chromatography, wherein a single chromatography cycle isbased on several consecutive steps, such as loading, wash, elution andregeneration, in continuous chromatography based on multiple identicalcolumns all these steps occur simultaneously but on different columns.Continuous chromatography operation results in a better utilization ofchromatography media compositions, reduced processing time and reducedbuffer fluid requirements, all of which benefits process economy.Continuous chromatography is sometimes denoted simulated moving bed(SMB) chromatography.

As previously mentioned each column may be loaded/packed, eluted,cleaned, and regenerated several times in the process. An essentialfactor for a reliable continuous chromatography process is the qualityof the columns used, and more specifically the similarity or evendensity of media in each column. If the columns are not identical, thetheoretical calculations will not be correct, and it will becomedifficult to design an efficient and robust continuous chromatographyprocess. However, the loading/packing of a column with chromatographymedia composition, is very complex in order to obtain repeatableresults. Even small differences in the number of plates or other packingproperties can have a huge effect on the end result.

A problem with conventional solutions is that performing continuouschromatography is a cumbersome, complex and time consuming operation.Often the process must be interrupted to perform reconnection of fluidcouplings/tubes, to perform packing of columns or to load a pre packedcolumn, to perform cleaning operations etc.

Thus, there is a need for an improved chromatography apparatus forperforming continuous chromatography.

Furthermore, even though chromatography apparatus which performscontinuous chromatography of the type mentioned above are known, forexample those sold under the tradename of AKTApilot by GE Healthcare,and these known instruments function well, providing a versatileinstrument which can be re-plumbed for different functionality ifneeded, these instruments lack some functionality, such that there areonly certain procedures in which they can be employed, and an extensionof that versatility would be commercially attractive, but is not easy toachieve with the competing restraints of instrument size, maintainingversatility, practical aspects such as ease of cleaning internally andexternally, and cost.

SUMMARY OF THE INVENTION

Embodiments of the present invention address the problems mentionedabove. Thereby, an object of the present invention is to provide achromatography instrument with one or more of: an increasedfunctionality, for example able to operate in conventional batchchromatography as well as continuous chromatography; is useable across awider range of applications; does not have a substantially increasedoverall size or manufacturing cost; and is simple to operate.

Good Manufacturing Practice (GMP) sets out guidelines for bioprocessingprocedures, which if followed require cleanliness standards.Advantageously, the standards are easier to achieve with the proposedapparatus, for example where fluid paths in the instrument have, in oneconfiguration at least, a continuous flow path with no substantivestagnant portions, thereby providing complete cleaning without the needto break down the fluid conduits. Embodiments of the proposed instrumentprovide a sanitary small-scale chromatography instrument suitable forboth GMP and non-GMP work. Functionally wide flow and pressure ranges ofthe instrument makes it fit for both production of technical batches andscale-up studies as well as small-scale production of GMP-gradematerial. The high accuracy and flow range of the pumps enables precisegradient formation, covering a large range of chromatography columnsizes and more repeatable results.

In embodiments, a modular construction provides increased functionality,for different uses. Interactive control software allows changes to bemade in real-time and unexpected deviations to be quickly identified.The small, bench-top size frees up lab space. The instrument allowsin-situ column packaging, i.e. the ability to compress chromatographymedia in the column, or each column where two or more columns are used,whilst being connected to the instrument, and without having to thendisconnect any fluid conduits prior to performing chromatographicprocedures.

According to an aspect of the invention, there is provided achromatography instrument as claimed herein having features set out thein independent apparatus claims, are further preferred features set outin the dependent apparatus claims.

According to another aspect of the invention, there is provided a methodfor operating a chromatography instrument as claimed herein havingfeatures set out the in independent method claims, are further preferredfeatures set out in the dependent method claims.

The invention extends to any features described herein. Whereembodiments show and/or describe features in combination herein, a claimwhich includes just one or a subset of said combined features isexpressly considered to fall within the ambit of the invention disclosedherein.

More advantages and benefits of the present invention will becomereadily apparent to the person skilled in the art in view of thedetailed description below.

DRAWINGS

The invention will now be described in more detail with reference to theappended drawings, wherein:

FIG. 1 shows a pictorial view of a new chromatography apparatus;

FIG. 2 shows schematic representation of the apparatus shown in FIG. 1 ;and

FIGS. 3, 4 and 5 show configurations of the apparatus shown in theprevious Figures.

DETAILED DESCRIPTION

FIG. 1 sows a chromatography apparatus 100 according to an aspect of theinvention. The apparatus includes, but it not limited to, individualmodules 1 to 25 as listed below, at least some of which are demountablefrom an apertured front panel 120 of a housing 110 of the apparatus 100and mounted thereon in one generally vertical plane, such that theliquid connections required between modules can be made only at thefront face 120. In practice the demountable modules have no more thantwo standard sizes which can, if needed, be repositioned on the panel120 to suit a different procedure. Each module has a serial buscommunication connection and power connection so that its physicalposition is immaterial to a controller for example located in thehousing 110, or located remotely. Thereby, the modules can be regardedas modular and thereby repositionable and/or interchangeable.

The chromatography apparatus shown in FIG. 1 has the following modulemodules:

-   -   1 Control panel    -   2 pH monitor    -   3 Outlet valve 1-3, port 1 can be used for waste    -   4 Outlet valve 4-6    -   5 Conductivity monitor    -   6 Outlet valve 7-9    -   7 Pre-column Conductivity monitor    -   8 Column valve, including pre- and post-column pressure sensor    -   9 Bottles for pump rinsing solution    -   10 Inlet valve A1-A3    -   11 Inlet valve A4-A6    -   12 Inlet valve B1-B3    -   13 Inlet valve B4-B6    -   14 Fixed rubber feet    -   15 Adjustable feet    -   16 System pump A    -   17 System pump B    -   18 Flow restrictor, including system pressure monitor    -   19 Mixer module    -   20 Mixer valve    -   21 Air trap valve, including air sensor    -   22 Air trap    -   23 ON/OFF button    -   24 Holder for in-line filter (typical filterapsule shown)    -   25 UV monitor

Modules can be omitted or repositioned as explained above. It will beapparent that some modules can be replaced with other modules or thespace left by an omitted module can be filled with a blanking plate (seee.g. 26 FIG. 4 ). More than one of the same numbered modules can be usedwhere necessary.

Fluid interconnections between the fluid manipulating modules of theapparatus i.e. all the modules listed above except modules 1, 15 and 23,and external modules for example sample input reservoirs, buffer fluidreservoirs, chromatograph column(s) and fraction collection equipment,all not shown in FIG. 1 , are made via fluid conduits in this case inthe form of flexible plastics tubing, which can be readily coupled anduncoupled to corresponding ports of the fluid manipulating modules, inany desired configuration, for example using a coupling as disclosed ina related application GB1710279 filed 28 Jun. 2017 incorporated hereinby reference.

FIG. 2 shows one possible liquid interconnection configuration betweenthe main modular modules of the chromatography apparatus, connected inthis case to two chromatography columns 200 and 300, although theapparatus allows any workable interconnection between modules andadditional parts such as multiple columns, and liquid reservoirs.Reconfigurable liquid interconnections are denoted by short chain dottedlines 80.

At the heart of the apparatus 100 is the column valve 8, which in thiscase has a construction as disclosed in our co-pending patentapplication filed on the same day as this application, and having thetitle ‘VALVE UNIT FOR A CHROMATOGRAPHY APPARATUS’ and is incorporatedherein by reference. The value unit 8 provides multiple switching offlow for allowing flow in one or both 20 columns 200/300 in eitherdirection (up or down in the drawing). The user can select upflow ordownflow, or select to bypass one or both columns. The flow can bedirected to waste or to the next component in the flow path. The columnscan also be connected in series. The Column valve includes pre-columnand post-column pressure sensors. In addition the valve has a port 150which can be used to change the volume of hydraulic cylinders 210 are310 which are part of the columns 200 and 300, for example to providecompression of the columns' contents, also known as column packing. Thatpacking procedure can be automated. With such a system column diametersof between about 25 and 250 mm have been found to be packable in thisway. The columns can be pre-packed, but rinsed and re-consolidated withthe aid of pressure sensors in the value unit 8 measuring back-pressureresulting from pressure within the columns and in accordance with toknown protocols, for example as described in WO200704549 1, whichdisclosure is incorporated herein by reference.

The remaining system 100 comprises:

-   -   Inlet valve groups A and B, 10, 11, 12 and 13, suitable for        providing selectable liquids including sample containing liquids        buffer solutions, and cleansing fluids;    -   The inlet valves supply two system pumps, here each having a        pair of pistons and associated one-5 way valves, providing a        variable flow rate of between 0-600 nil per minute each (1200        ml/min max), with a high volume and resolution of flow, enabling        accurate flow rates to be maintained. Such accuracy enables good        repeatability of results for a wide range of column diameters;    -   The pumps supply, in series a flow restrictor 18, which includes        a system pressure monitor, a mixer valve 20, and a mixer module        19, before pumped liquid is diverted to the column valve unit 8;    -   Any entrained air can escape via an air trap valve 21, and an        air trap vent 22, which vent also has an air escape from the        columns 200 and 300. The air trap may be constructed in        accordance with pending application GB1713993 filed 5 Apr. 2017,        which disclosure is incorporated herein by reference;    -   Once liquids reach the column valve unit they can be routed in        accordance with the arrangement described in said co-pending        application with the title ‘VALVE UNIT FOR A CHROMATOGRAPHY        APPARATUS’, and thereby numerous modes of chromatography can be        performed, from simple batch work, where a straightforward        chromatographic separation process is performed using just one        column, to procedures which more closely copy larger scale        commercial procedures where two or more columns can be employed,        one being readied for use while the other is being used for        separation. The valve port numbering used is the same as that        used in said co-pending application and here has the same        arrangement;    -   Output from the chromatography column(s) is passed out through        port 120 to: a conductivity monitor 5, a UV light absorption        monitor 25, and a pH monitor 2, and is thence directed into an        appropriate storage vessel in dependence on the signals from the        three monitors, and thereby, separated fractions are collected        in an appropriate vessel 501. Column washings can be collected        in a waste vessel 500;    -   The long chain dotted lines in FIG. 2 represent a system bus 500        which carries signals and power to and from the modules        mentioned above, to and from a controller 600. It will be        appreciated that controlling and monitoring signals may be        transmitted wirelessly according to known protocols, doing away        with the need for a communication bus. The chromatography system        100 includes also a display screen 30. Software running on the        controller will display plural icons on the screen 30 and allow        user manipulation of the icon on the screen to drag and drop the        icons to form a series of icons representative of a user defined        chromatography control method, for ease of use.

FIGS. 3, 4 and 5 show the system connected with tubing for variousconfigurations, where only some of the modules referenced in FIG. 1remain in place in these figures, and the apertures left by removedmodules are blanked off with blanking plates 26, screwed into place overthe aperture to prevent accidental liquid ingress into the housing 110.

In FIG. 3 a system 100′ with a configuration of modules suitable forregulated environments where systems are custom-built in a factory. Thesystem is delivered mounted, calibrated, and performance tested andsuitable for work in GMP environments. FIG. 4 shows one system with somemodules removed, and FIG. 5 shows a system 100′″ with more modules inplace, similar to FIG. 1 , and showing typical tubular interconnections80.

In use, modules are easily removed or added to the system andinstallation finalized through a one-click activation in software whichcan recognize each module. The software can provide comprehensive andcustomizable operational control as well as pre-emptive maintenance. Inaddition to the modules described above, input-output communicationmodules can be used to interface with analog and/or digital externalsensors or other equipment such as automatic fraction collectingdevices. The wide flow rate and pressure ranges enables more than40-fold scaling in the range 25 to 250 mm internal diameter columns.This wide range makes the apparatus suitable to bridge the transitioninto GMP environments.

The packing (and re-packing) of chromatography columns, using the systemdescribed above is controllable fully by the controller 600 initiated bythe control panel 1. The controller 600 is able to drive the a displayscreen 30 (FIG. 2 ) to aid visualisation of the packing process andprogress. The control software includes an accessible column packingrecord. Columns packing records can therefore be defined, created, andupdated from the software for traceability and quality assurancepurposes. In addition, the record can be used to monitor columnperformance and provide statistics for usage, separation performance,and packing intervals.

The display screen can provide a process visualization which quicklygives an operator an overview of the system's function, progress throughoperational steps and alarms, only providing the desired amount ofinformation at each step. The active flow path is always displayed inthe process visualisation to minimize user errors. Real time changes canbe made by selecting the appropriate process on the visualizationscreen, e.g. selecting or dragging icons on the screen. Control,graphical interfaces are provided for specific sections, such as thecolumn valve 8.

Preprogrammed steps are employed but these can be modified and saved asuser-defined steps for added customization.

The system described and illustrated above is designed for sanitaryenvironments. For example, the system chassis 110 is flat or curvedwithout joints, gaps or significant concavities, other than at the edgesof the faces, which makes it easy to wipe down and reduces the chance ofdust and liquid trapping. The pH monitor 2 has in-line calibration andthe column valve 8 provides in-process column packing, so a closed flowpath through operations can be employed, meaning that no breaks in thefluid path need be made throughout one or more chromatography columnpacking/regeneration stages and throughout the separation operation,

The invention is not to be seen as limited by the embodiments describedabove, but can be varied within the scope of the appended claims as isreadily apparent to the person skilled in the art.

1. A chromatography system comprising: a plurality of modules includingat least one pump and a column valve unit connectable to pluralchromatography columns; and a controller, the controller being operableto control the or each pump and the column valve unit to performdifferent chromatographic processes, including chromatography employingjust one column, as well as chromatography employing two or more columnsby selective valve opening in said column valve unit, and wherein atleast one of said plurality of modules is demountable from an aperturedfront panel of a housing of the chromatography system.
 2. Thechromatography system as claimed in claim 1, wherein said at least oneof said plurality of modules is mounted in one generally vertical plane,such that liquid connections required between respective modules can bemade only at a front face of the chromatography system.
 3. Thechromatography system as claimed in claim 1, wherein said selectivevalve opening allows a reversal of flow directions in use in one or moreof said plural chromatography columns.
 4. The chromatography system asclaimed in claim 1, wherein the controller is operable to control saidmodules according to software, and further comprising a display screen,said software being suitable to display plural icons on said screen andallowing user manipulation of the icon on the screen to drag and dropthe icons to form a series of icons representative of a user definedchromatography control method.
 5. The chromatography system as claimedin claim 4, wherein the user defined method includes a continuouschromatography process employing said two or more chromatographycolumns.
 6. The chromatography system as claimed in claim 1, wherein thecontroller is further operable to perform one or more of column packing,column packing testing, and cleaning of at least a part of the system.7. The chromatography system as claimed in claim 1, further comprisingplural chromatography columns, each column including a chamber ofchangeable volume for housing chromatographic separation media and anadapter moveable to increase or decrease each said volume, and whereinthe column valve unit is in fluid communication with each said adapterand is selectively operable to move independently or collectively eachsaid adapter by means of fluid pressure changes to consequently changeeach said volume and in use to cause compression or relief fromcompression of media within each said column volume.
 8. Thechromatography system as claimed in claim 1, wherein the plural modulesare interchangeably mountable in apertures of one generally verticalface of the system housing, the modules being adapted for selectivefluidic interconnection by tubing, and wherein at least one of saidmodules includes said column valve unit.
 9. The chromatography system ofclaim 8, wherein the modules are adapted for selective fluidicinterconnection by tubing substantially at said one generally verticalface such that in use the modules and tubing occupy a generallyvertically extending volume to minimize the footprint of the system. 10.The chromatography system as claimed in claim 8, wherein, other thansaid one generally vertical face, the system housing has flat or curvedfaces without joints other than at the edges of the faces.
 11. Thechromatography system as claimed in claim 1, wherein the modulescomprise one or more of: a pH monitor; an outlet valve; a conductivitymonitor; a column valve; an inlet valve; a system liquid pump; a flowrestrictor; a mixer; an air trap; an air trap valve; and air trap ventand a UV monitor.
 12. The chromatography system as claimed in claim 11,wherein output from the chromatography column(s) is passed out through aport to a conductivity monitor, a UV light absorption monitor, and a pHmonitor, and is thence directed into an appropriate storage vessel independence on the signals from the three monitors such that separatedfractions are collected in an appropriate vessel.
 13. The chromatographysystem as claimed in claim 12, wherein output from column washings iscollected in a waste vessel.
 14. The chromatography system as claimed inclaim 1, wherein the system includes two liquid pumps, one of said pumpsbeing selectively operable alone or both pumps being selectivelyoperable together, thereby to provide a range of fluid flow which issuitable for more than one mode of chromatography process.
 15. Thechromatography system as claimed in claim 1, further comprising apre-column conductivity monitor and/or adjustable feet.
 16. Thechromatography system as claimed in claim 1, wherein the column valveunit further comprises a port which can be used to change the volume ofhydraulic cylinders so as to provide compression of the contents ofcolumn(s).
 17. The chromatography system as claimed in claim 1, whereinthe chromatographic processes include a continuous chromatographyprocess that includes control of at least one pump and where the columnvalve unit is switched to provide fluid flow from the at least one pumpin both directions in each of the columns employed.